Sulphurizing chemical compounds



Patented Au 13, 1940 PATENT OFFICE 1 2,210,877 S PHURIZING CHEMICAL COMPOUNDS Ulric B. -Bray, -Palos Verd signor to Union Oil Los Angeles, Calif., a

Company of corporation of California es Estates, calm, as-,

California,

No Drawing. 'Application January 12,1937, Serial 1m 120,244

8Claims.

This invention relates to a method for the sulphurization of oils, esters and various other chemical compounds, and the object of the inven-- tion is to provide a process which will keep the suiphurizing reaction from proceeding too rapidly or too far,v will be adapted to eflicient control, and will yield well defined chemical products relatively free from coke and other insoluble materials.

' The invention resides primarily in supplying sulphur to the reacting mass of any of the above indicated or other desired sulphurizable chemicals only as fast as the sulphur is used up beyond the certain concentration required for directing the reaction. In other words, the sulphurrequired for the reaction is added from time to time in small increments, the addition being controlled so that the sulphur does not exceed concentratlons beyond those necessary for a con trolled reaction, whereby excessive formation of sulphurized bodies and coke-like or other insoluble polymers or similar materials which would otherwise result, will be avoided.

In practicing the invention the sulphurization will ordinarily be accomplished in conjunction with the application of heat according to well known procedures applied to the respective materials to be sulph A quantity of sulphur will be added to the mass to be reacted upon in only a relatively small proportion beyond that quantity the regulated addition of necessary for directing the reaction. Such small proportion will be such that it will be used up readily without opportunity for the type of reaction to pass out of control. As a result only the frequent additions of further small quantities of sulphur added only as the reacting mass properly takes them up, only that sulphur will be present at any given time which is necessary to the requirements of the reaction, at least up to the point of saturation.

I have found that this procedure of introducing the sulphur in small increments in step with the requirement of the reaction produces eflicient and satisfactory sulphurization very readily, a result which has tained by temperature control or other controls which have been unde In other words, while temperature control is important, an additional control of great eil'ectiveness is found in sulphur b relativ ly small and frequent increments.

In'the case of mixtures wherein the sulphur is I extent-it is preferred soluble to only a limited adding the sulphur at a duction of various not been heretofore at that a melted sulphur phase be not present because of excessive reaction at the surface which tends to produce the objectionable coke-like or other insoluble materials above mentioned. By rate only suilicientv to satisfy the solvent power of the reaction mass for the sulphur, the needs of the reaction are best met and no opportunity is ail'orded for the reaction to go out of control or to progress too rapidly thereby to produce objectionable materials such as s'ul-, phurized polymers.

By employing this means of controlling the sulphurlzation, I have found a distinct improvement over results obtainable'hereto'fore by simply heating all of the required sulphur along with the chemical'to besulphurized. For example, I have found the present process to be highly satisfactory in thesulphurization of dibutylphthalate. Also, petroleum oils and various fractions of petroleum oils, particularly the oleflnic or unsaturated petroleum fractions, are readily sulphurlzed to produce desired compounds without pronounced tendency toward the formation of bodies of excessive'molecular weight either through the influences of substitution saturated materials may be sulphurized in similar fashion without danger of heaving the reaction extend too farand produce heavy undesirable products. The process may be applied not only to petroleum oil fractions but also to vegetable and animal oils. Such sulphurized compounds are frequently desired in connection with the protypes of lubricants, extreme pressure gear oils, cutting oils, emulsiflable oils,

so-called soluble oils and kindred materials So far as concerns sulphur-bearing chemicals in general, the application of the process producing such sulphurized compounds will have wide application. x

In addition to aiding sulphurization by the addition of the required sulphur only in small increments at spaced intervals, the sulphurization may also be controlled by conducting the same under pressure at suitable temperatures. It necessary pressure relief valves may be employedto prevent the escape of hydrogen sulphide in those instances where it is formed.- By operating under pressure, the most suitable temperature conducive to the desired results may be employed, and volatilizable materials are maintained in liquid or unvaporized condition. For example, in some instances a temperature of 350 F. to 550 F. is most satisfactory for purposes of sulphurization.

or polymerization or otherwise. In addition to unsaturated materials,

whereas such temperatures present difliculties at 55 pressure ample 550 F.

' coincident normal pressures with materials of a volatile" nature. For that reason pressures of suitable degree, for example 10 to I pounds may be employed. As a s ecific example, gasoline or petroleum fractions either a cracked or a straight run distillate, may be easily sulphurized under at tempe tures above 400 F., for exturesunder suitable pressure, pounds in a pressure vessel or coil,

.incipient cracking of the gasoline to produce oleflnic or unsaturated materials may be prod Spray oils and lubricating oils may and sulphurized. Similarly, sulphurization of unsaturated fractions/from gasoline, kerosene or other petroleum fractions already containing oleflnic fractions, or similar fractions which have or concentrated and c largely of olefinics and unsaturates may be conveniently sulphurized under pressure. In sulsuch unsaturates, the sulphur primarily ably is controlled so A of hydrogen and consequent formation of hydrogen sulphide takes place. In applying pressures for sulphurization purposes wherein coincident cracking takes place or wherein coincident cracking is avoided, such pressures may be used not only where the sulphur is added in a plurality of excessive increments to obtain the resul scribed but also where the sulphur is added substantially at one time according to the more usual method of sulphurization procedures.

are furnished as invention. They are not to be taken as limitin beyond the scope of the appended claims inasmuch as it is obvious that the process may be modified and expanded both as to its details and its application in many ways apparent to those skilled in the art.

I claim: I

1. A process for sulphurizing petroleum fractions which comprises heating saturated petro-k. leum fractions in the liquid phase in the presence of free sulphur under pressures between about 10 pounds and about 750 pounds per square inch and at temperatures between about 350 F. and about 550? 1?. whereby unsaturation elected and P i ts of increments fy the unsaturation as it is ts destantially no sisting of sulphurizable of said fractions is coincidentally sulphur enters at the such unsaturation, the sulphur being supplied .to the reaction only substantially only suflicientto satisproduced and as the sulphur is required, whereby cess of hur over immediate sulphur requirements present at any given stage of the reac- 2. A process according to claim 1 wherein sub stantially no molten sulphur is present at any stage.

substantially no ex-' cessive 3.7A process for sulphurizing petroleum iractions which comprises heating gasoline and kindred fractions at temperatures between about 400 F. and about 550 F.,and at-pressures approximating 400 pounds per square inch in the presence of free sulphur, the sulphur being added to the petroleum fraction only in a succession of small increments sufllcient approximately only to satisfy the requirements for sulphur at any given stage and without-the presence of excess sulphur at any stage of the reaction.

4. A method for sulphurizing pounds comprising heating a saturated sulphunzable chemical compound in the liquid phase in the presence oi free sulphur under pressure and temperature conditions effecting compound and coincidentally causing sulphur to enter the molecules of the compound at the points of such unsaturation, the free sulphur being supplied to the reaction only in small successive increments, each increment being substantially only sufllcient to satisfy the unsaturation as it is produced and as the sulphur is required whereby subexcess of sulphur' over immediate sulphur requirements is present at any given stage of the reaction.

5. Amethod according to claim 4 wherein the chemical compound treated is a mineral oil frac- I. A method according to claim 4 wherein the compound treated is selected from the group conesters and ester oils.

8. A method accord ngvto claim 4. .wherein the compound is dibutylphthalate.

name 3'. Bruin according fijwherein the 

